Printing of fabrics



Aug. 11, 1 959 J. GRIFFITHS ETAL' PRINTING OF FABRICS Filed Aug- 2, 1957 2 Sheets-Sheet 1 III I U J IHCK GRIFFITHS W G Hnmmvo INVENTORS YATTORNEY 1959 .1. GRIFFITHS ET AL 2,899,264

PRINTING OF FABRICS Filed Aug. 2, 1957 2 Sheets-Sheet 2 Fig. 3.

JncK GmFrmls W G Ham/mo INVENTORS ATTORNEY Unite 2,899,264 Patented Aug. 11, 1959 ice PRINTING F FABRICS Jack Griffiths, Manchester, and William Gordon Harland, Wilmslow, England, assignors to The British Cotton Industry Research Association, Manchester, England, a British association Application August 2, 1957, Serial No. 676,001

12 Claims. (Cl. 8-148) This invention concerns the printing of textile fabrics and yarns, especially cellulosic fabrics and yarns.

The object of the invention is to provide a cheaper and more efficient process of, and means for, fixing vat and sulphur dyes after they have been applied to the fabric or yarn in the initial stages of a two-phase printing process.

According to the invention a method of printing a textile fabric or yarn, especially a cellulosic fabric or yarn, with a vat or sulphur dye, includes fixing the dye on the fabric or yarn by passing the fabric or yarn, printed, and treated with the chemicals necessary for reduction of the dye to a soluble form, .around a system of heated, rotating cylinders, the fabric or yarn being held against part of the periphery of each cylinder by a traveling band of fluid-tight material, and passing substantially directly from the peripheral surface of one cylinder to that of the next, the heating of the cylinders and the speed thereof being so arranged that the fixation is adequate on leaving the system.

A further traveling fluid-tight band may be interposed between the fabric or yarn and the cylinder peripheries so that the fabric or yarn is sandwiched between the two bands to be conveyed thereby.

The invention also comprises apparatus for carrying out this method, including a system of rotatably mounted cylinders, means whereby at least some of said cylinders may be heated, and a band of fluid-tight material, all arranged so that fabric or yarn printed with dyestutf may be conveyed between the band and part of the periphery of each cylinder, passing substantially directly from the peripheral surface of one cylinder to that of the next.

The apparatus may comprise a pair of bands of fluidtight material between which the fabric or yarn is conveyed over the cylinder peripheries.

The invention will now be described further, with ref erence to the accompanying drawings in which:

Fig. 1 shows diagrammatically one embodiment of the invention;

Fig. 2 shows diagrammatically a modification of the embodiment shown in Fig. l, and

Fig. 3 shows diagrammatically a further embodiment of the invention.

In the embodiment of Fig. 1 three cylinders 11 are mounted side-by-side, with their axes parallel to each other. The cylinders are mounted for rotation and suitable driving means (not shown) are provided for rotating them. The spacing of the cylinders is such that only a small space is left between the adjacent parts of their peripheries. In each of the two such spaces are disposed two small-diameter horizontally disposed cylindrical rollers 12, one immediately above and one immediately below the line of centres of the cylinders, and at corresponding positions adjacent the opposite part of the periphery of one of the end cylinders, are mounted single rollers 13, the top one being an entrance roller and the bottom one an exit roller. The purpose of these rollers will be described shortly.

Means for heating the cylinders are provided, for example pipes 16 for injecting steam into their interiors.

An endless band 14 of cotton or like fabric impreg-' mated with rubber or other suitable fluid-tight material, of Width commensurate with the length of the cylinders 11 is constrained to pass around a substantial part of each cylinder periphery. This is achieved by passing the band 14 under the top entrance roller 13, over the upper part of the first cylinder periphery, under the upper roller 12 between this cylinder and the second cylinder, over the upper part of the second cylinder, under the upper roller 12 between the second and third cylinders, round the third cylinder, over the lower roller 12 between second and third cylinders, under the lower part of the second cylinder, over the lower roller 12' between the first and second cylinders, under the lower part of the first cylinder, and finally over the exit roller 13. The disposition of the rollers 12, 13 and cylinders 11 is such that the distance travelled by the fabric or yarn 15 out of contact with the heated cylinders 11 is as short as possible. Rollers 18 are provided to enable the endless band 14 to return from the exit to the entrance roller of the machine .and washing means (with or without drying means 19) for cleaning it if necessary.

In use, fabric or a sheet of yarn 15 (which is narrower than the length of the cylinders 11) to which vat or sulphur dyes have been applied in a printing machine and which has been treated with the chemicals required for reduction of the dyes to a soluble form, is passed over the entrance roller 13 and is carried along between the band and the cylinder peripheries. In order to reduce the possibility of marking off it is desirable that the printed face of the fabric should be in contact with the endless band. The temperature of the cylinder peripheries and their speed of rotation is so arranged that fixation is adequate on leaving the exit roller 13.

It will be appreciated that an important feature of the invention is that the fabric or yarn is passed from one cylinder to the next substantially directly. Where a change of direction is involved, as in the embodiment of the Fig. 1 auxiliary rollers must be accommodated and this limits thedirectness of the pass.

The advantage of the invention compared with known techniques are a substantial saving of thermal energy andmore accurate control of working conditions. Efficiency is therefore increased, costs decreased, and the incidence of marking off and of flushing substantially reduced. Furthermore no enclosure is necessary for the arrangement, which occupies less space than known arrangements. The arrangement necessitates only af small working up time and is therefore suitable for short runs. i

The invention'is of coursenot limited to the details of the embodiment described. Numerous cylinder arrangements, for example, are possible. Furthermore, steam may be injected into the spaces between the cylinders via suitable pipes 17 to maintain the required temperature and humidity whilst providing an air-free atmosphere on the short runs of fabric or yarn which are notin contact with the cylinder surfaces. Although fabric impregnated with rubber is a suitable material for the endless band, other impregnating materials are also useful, in particular high density polyethylene. It is desirable that the belt shouldbe smooth'and of course should have no affinity for the dyes used. 7

The modified embodiment shown-in Fig.2 is pre ferred in cases Where the tendency for marking-offis not completely eliminated but persists due to colour which has been forced through the fabric during printing being transferred to a cylinder and then from that cylinder to other parts of the fabric.

Referring to Fig. 2 (in which the reference numerals for the various parts are the same as are used in Fig. 1 for the corresponding parts) it will be seen that an additional fluid-tight band 14a,is used. The fabric or the like 15 is sandwiched between the bands 14, 14a and any possibility of marking-01f as described in the preceding paragraph is prevented. The additional band 14a will have washing means (with or without drying means) 19a for cleaning it if necessary.

Referring now to the embodiment of Fig. 3 a conventional dryer range with ten cylinders 21 each with steam inlet pipe 26 is used. In this case endless bands 24, 240 (having washing means 19, 19a respectively with or without drying means) convey the fabric or yarn 25 from :1 padding arrangement 27 around the cylinders 21. As the fabric or yarn 25 is conveyed over successive cylinders, first the band 24 then the band 24a is against a cylinder periphery (the fabric or yarn 25 being likewise reversed relative to the successive cylinders) and the fact that all the cylinders 21 do not rotate in the same direction does not matter.

There is only a slight disadvantage compared with an arrangement of the type illustrated in Figs. 1 and 2, that being that it is not possible to utilise quite as much of the periphery of each cylinder. On the other hand this arrangement has some important advantages. The cylinder temperatures may be arranged to be diiferent, for example, gradually increasing as the fabric progresses through the range. Steam economy can be achieved thereby, and we consider it possible that an improvement in colour yield and definition may also be achieved.

Secondly, by allowing one band to follow the altcrnative path, shown in dotted line in Fig. 3, the last cylinder 21 could be used partially to dry the printed material and this would minimise marking off during handling prior to oxidation and soaping. Thirdly, and perhaps most important of all, it allows of the possibility of utilizing the drying cylinders often provided as part of conventional printing machines, for the purpose of developing and fixing the colours. Thus, for example, caustic soda and sodium hydrosulphite could be padded onto the printed fabric before the latter reached the cylinders. The logical conclusion of such a procedure is a completely continuous process consisting of the successive steps of printing, padding, steaming, oxidation, soaping, and drying. In such processes the cost of the normal steaming step is saved.

What we claim is:

1. In apparatus for heat treating a web of material to fix a dyestufi thereon: an array of internally heated rotatable cylinders in non-contacting adjacence with their axes parallel, an endless flexible band of fluid-tight material wider than the web to be treated and extending sinuously and progressively from one cylinder to the next and around a substantial peripheral area of each, means for guiding said band along a return lap out of contact with said cylinders, and means for introducing the web to be treated beneath said band as it encounters the cylinders and guiding the web away as the band commences its return lap, whereby said web may be advanced through a path of travel in which it is subjected to the heat of said cylinders while being shielded from the atmosphere by said band.

2. The combination with the elements defined in claim 1, of a second endless flexible band extending around said cylinders beneath said first-named band, and means for guiding said second hand along a separate return lap, whereby said web may be advanced through its path of travel while sandwiched between said bands.

3. The combination with the elements defined in claim 1, of means for injecting steam into certain of the spaces between adjacent cylinders.

4. The combination with the elements defined in claim 1, of means maintaining said cylinders at successively different temperatures.

5. The combination with the elements defined in claim 1, of means disposed along the return lap of said band for cleaning it.

6. In apparatus for heat treating a web of material to fix a dyestuff thereon: an array of internally heated rotatable cylinders in non-contacting adjacence with their axes parallel, an endless flexible band of fluid-tight material wider than the web to be treated and extending sinuously and progressively from one cylinder to the next and around a substantial peripheral area of each, means for guiding said band along a return lap out of contact with said cylinders, a second endless. flexible band extending around said cylinders beneath said first-named band, means for guiding said second band along 21 separate return lap, means for introducing the web to be treated into the space between said bands where they come together and guiding the web away where the bands separate, and means disposed along said return laps for cleaning said bands respectively. 7

7. A method of heat treating a web of material to fix dyestufi with which the web is impregnated, which consists in advancing the web longitudinally to bring it into contact with the peripheral faces of a succession of adjacent internally-heated cylinders, maintaining an endless fluid-tight band in covering relation to said web to shield it from the atmosphere and press it against said cylinder faces, and rotating said cylinders at peripheral velocities equal to the speed of web advancement.

8. A method of heat treating a web of material to fix dyestufi with which the web is impregnated, which consists in sandwiching the web between a pair of fluidtight bands, advancing said bands and web to bring the sandwiched elements into contact with the peripheral faces of a succession of adjacent internally-heated cylinders, and rotating said cylinders at peripheral velocities equal to the speed of advancement.

9. A method of heat treating a web of material to fix a dyestuff with which the web is impregnated, which consists in sandwiching the web between a pair of fluidtight bands, advancing said bands and web along a sinuous path of movement which brings the sandwiched elements successively under and over a series of adjacent internallyheated cylinders and in contact with said cylinders along substantial peripheral areas thereof, and rotating alternate cylinders in opposite directions and at peripheral velocities equal to the speed of web advancement.

10. A method as defined in claim 9, in which said cylinders are maintained at different temperatures.

11. A method of fixing a dyestuff on a textile material, especially a cellulosic web running continuously from a printing machine, comprising the steps of impregnating the material with the chemicals necessary for the reduction of the dyestutf to the soluble form, conveying the material around a plurality of internally-heated rotating cylinders by means of an endless fluid-tight band effec tive to hold the material against a substantial part of the periphery of each cylinder and pass said material sub-. stantially directly from the peripheral surface of one cylinder to that of the next.

12. A method of fixing a dyestuff on a textile material, especially a cellulosic web running continuously from a printing machine, comprising the steps of impregnating the material with the chemicals necessary for the reduction of the dyestuif to the soluble form, then conveying the material around a plurality of internally-heated rotating cylinders whilst sandwiched between a pair of endless fluid-tight bands effective to cause the material to pass over a substantial part of the periphery of each cylinder and substantially directly from the peripheral surface of one cylinder to that of the next.

(References on following page) 5 References Cited in the file of this patent 2,404,350

UNITED STATES PATENTS 189,371 Mather Apr. 10, 1877 1,737,149 Cohoe Nov. 26, 1929 5 1,820,048 Chase Aug. 25, 1931 749,084

6 Carlsen July 23, 1946 Stott Nov. 8, 1949 Williams May 8, 1951 FOREIGN PATENTS Great Britain May 16, 1956 

6. IN APPARATUS FOR HEATING TREATING A WEB OF MATERIAL TO FIX A DYESTUFF THEREON: AN ARRAY OF INTERNALLY HEATED ROTATABLE CYLINDERS IN NON-CONTACING ADJACENCE WITH THEIR AXES PARALLEL, AN ENDLESS FLEXIBLE BAND OF FLUID-TIGHT MATERIAL WIDER THAN THE WEB TO BE TREATED AND EXTENDING SINUOUSLY AND PROGRESSIVELY FROM ONE CYLINDER TO THE NEXT AND AROUND A SUBSTANTIAL PERIPNERL AREA OF EACH, MEANS FOR GUIDING SAID BAND ALONG A RETURN LAP OUT OF CONTACT WITH SAID CYLINDERS, A SECOND ENDLESS FLEXIBLE BAND EXTENDING AROUND SAID CYLINDERS BENEATH SAID FIRST-NAMED BAND, MEANS FOR GUIDING SAID SECOND BAND ALONG A SEPERATE RETURN LAP, MEANS FOR INTRODUCING THE WEB TO BE TREATED INTO THE SPACE BETWEEN SAID BANDS WHERE THEY COME TOGETHER AND GUIDING THE WEB AWAY WHERE THE BANDS SEPARATE, AND MEANS DISPOSED ALONG SAID RETURN LAPS FOR CLEANINIG SAID BANDS RESPECTIVELY. 